Bioproductivity and carbon stock dynamics of modal pine stands in the Left-Bank Forest-Steppe of Ukraine

Modelling a forest carbon budget is important for understanding the role of forests in the global carbon cycle, assessing their potential for climate change mitigation, and supporting evidence-based decisions in sustainable forest management. This study analyses the bioproductivity features of Scots pine (Pinus sylvestris L.) stands in the Left-Bank Forest-Steppe of Ukraine under varying forest site conditions. Mathematical models describing the dynamics of phytomass and carbon accumulation were developed separately for fairly infertile and fairly fertile site conditions. Based on these models, tables of bioproductivity for modal planted pine stands were compiled. The modelling approach was grounded on widely used conversion factors that simulate forest stand growth and biomass development processes. The pine stands under study in the Left-Bank Forest-Steppe exhibited slightly lower phytomass stocks compared to modal stands located in the recreational and health-improving forests of Kyiv region. It was found that the maximum mean annual increment of carbon stock in modal man-made 45-year-old pine stands in site class I occurs in fresh, fairly infertile site types, and at the age of 40 years in fresh, fairly fertile site types.